"Mwanawasa was a very courageous leader. He was very frank and wanted to change not only his country but the entire southern African region. We will greatly miss him," the radio quoted him as saying on arrival in Lusaka, late on Tuesday, for Mwanawasa’s burial.
Mwanawasa had been an outspoken critic of Mugabe, once referring to Zimbabwe as a "sinking Titanic".
At least 10 of the 15 African heads of state expected for Wednesday’s burial are already in Lusaka, officials said.
Besides Mugabe, Presidents Ian Khama of Botswana and Bingu wa Mutharika of Malawi and Lesotho Prime Minister Pakalitha Mosisili have arrived in the Zambian capital, Zambia National Broadcasting Corporation said on its website.
A representative of Britain’s Queen Elizabeth, the Duke of Gloucester and Lord Malloch Brown, Minister for Africa, have also arrived along with German and Chinese official delegations, the radio said.
A top US delegation will also attend the funeral, a White House statement said.
Tanzanian President Jakaya Kiwete, and South African President Thabo Mbeki, who is the chairperson of the 15-nation Southern African Development Community (SADC) are scheduled to deliver speeches at the occasion on behalf of their organisation.
The burial will follow a church service, according to the official programme.
Mwanawasa was until his death chairperson of the SADC and one of the few African leaders to speak out against Mugabe’s policies.
Mbeki took over the leadership of the SADC during a summit of the body in Johannesburg last month.
Mwanawasa, 59, who died in a Paris hospital on August 19 after suffering a stroke, will be buried at Embassy Park, situated outside the presidential secretariat.
Mwanawasa, married and father of six, was a trained lawyer.